Luminaire



June 19, 1928.

INVENTOR.

WILLIAM A.DOREY BYJMM ATTORNEYS.

June-19,1928. 1,674,165 4 w. A. DOREY I LUMINAIRE Filed June 15; 927 sSheets-Sheet 5 INVENZOR. WILLIAM A. DORE-Y ATTORNEYS.

Patented June 19, 1928.

UNITE stars {A TENT WILLIAM A. DOREY, OFNEWARK, OHIO, ASSIGNOR 1.1.HOLOIPI-IANEV COMPANY,,INO.,

on NEW YORK, N. Y., A CORPORATION on NEW YORK. i

. LUMINAIRE.

Application filed. June 15, 1927. Serial No. 198,998.

The object of the present invention is the construction of a prismaticglobe in which.

substantially all of the lightfrom the lamp emitted below the horizontalis gathered.

into a comparatively narrow strip and directed to the road surface toproduce a reasonable approximation of uniform intensity.

This is accomplished by means of a combination of annular lens formswith their axes set at varying inclinations in a vertical plane(to-operating in part with prisms parallel to the plane of the lens axesand in part with vertical prisms both the parallel and vertical prismsbeing adapted to refract the light toward the vertical plane through thelens axes. The proportion of parallel and Vertical prism forms willdepend largely on the mechanical limitations imposed on the parallelprisms by the requirementsof mold relief. While the invention has beendescribed with reference to highway or street lighting it is adapted tomany other luminaires where directional light is desired, that is tosay, where it is desired to light a plurality of defined areas.

in combination .with a reflector, placed above the globe andintercepting the upward light from the lamp and reflecting it to theglobe at angles permitting eflicient transmissione Such a reflectorwillbe approximately hemispherical in shape with the c'enter of thesphere at or near the center of the light source so that the reflectedrays will pass back through or near the light, source and therefore betransmitted by the globe -i'ln much the same directionsaslight'raysproceeding direct from the source to the globe. In somecases it will be desirable that portions of the vertical contour of thereflectorv will vary'from a hemispherical shape to-.

' tained,

In the drawings, Fig. 1 is an elevation of the inner hemisphere of theglobe in a plane of symmetry of the structure bisectedto \show theprismatic'formation in cross secion.

Fig. 2 is an elevation of the outer hemisphere in the same plane as Fig.l similarly bisected.

Fig. 3 is an elevation of the inner hemi sphere in the plane 33 of Fig.1 bisected to show the prismatic formation 'in' cross. section. a

.Figr 4.- is an elevation of the outer hemisphere in the plane 44 ofFig. 2 similarly bisected.

Fig. .5 is a vertical cross section in the same, plane as Figs. 1 and 2showing the globe used in connection with a hemispherical reflector. n

Fig. 6 is a similar cross section in which 2113 contour; of thereflector has been modie "In Figs. 1,v 2 3 and 1, the construction issymmetrical with respect to Verticalplanes 7 3+3, 4 l,1-1 and 2-2respectively, the The globe is primarily designed for use center of ahemispherical bowl 8, having a smooth interior surface 9, and on its.outer surface a series of annular lens surfaces 10. At 11.11 the lensconstruction on the outer surface is divided into an upper section 12and a lower section 13. The location of the plane offdivision 1111 isdetermined by the vertical angle 14. Fig. 3 and is the angle at which itis desired to deliver the maxi mum intensity of light from theluminaire. Lens surfaces 15 and 16 in upper. section 12 and all thoselying between, them are formedabout the axis 17, 3, and designed torefract light parallel to that axis. In order to obtain eificient.transmissionof light it is desirable that the lens surfaces lyingbetween surface l6'and, the extreme lens'surface 18 shall not make agreater angle with. the spherical surface of the bowl 19, Fig. 3.

In lower section 13, lens surface 20 immediately adyacent to surface 11in the upper section is formed about axis 17 and designed to emit lightrays parallel to that axis. The lens surfaces between 20 and the extremelens surface 21 are formed about axes of successively lower inclinationand the angularity of the surfaces with reference to the sphericalsurface of the bowl is increased gradually but at a. more moderate rateof increase than in the upper section so that the light rays are benttoward the axis 17 but at increasingly divergent angles with referenceto it as the extreme surface 21 is approached and owing to thesystematic lowering of the angle of the axes of these lens surfaces thisdivergence is greater vertically than laterally thus bringing theresultant distribution of light into a wide strip in line with theroadway but not sufficiently concentrated for the best efficiency.

In Figs. 2 and 4, 22 is a hemispherical bowl having a smooth outersurface 23 and having on its inner surface smooth sections 24, andsections 25 provided withprisms parallel to plane 41-4 and sections 26provided with prisms radial about the vertical axis of the bowl. Thisouter bowl is designed to envelope the inner bowl Figs. 1 and 3. Thelower surface of flange 27 bowl 8, Figs. 1 and 3 rests on the uppersurface of the flange 28 bowl 22, Figs. 2 and 4. Section 25 is opposedto the central portion of section 13, 3 and the prism structure onsection 25 is designed to receive the refracted light rays from thelower part of the inner bowl and deviate them still more toward theaxial plane so as to bring them within the beam strip required forlighting the part of the road nearest to the luminaire.

It is not possible to use this structure over the whole surface opposedto the lower section 13 of Fig. 3 because the plunger pressing thisinner surface of bowl 22 operates vertically and separating surfacesbetween the operative refracting surfaces must relieve vertically. Theextreme separating surface 29 Fig. 2 receives a portion of the lightfronrthe inner bowl and refracts it outward from the plane 4-& and theresultant emission is not in a useful direction, the refracting surface30 receives a much greater portion of the light from the inner It isimportant, however,

bowl and refracts it toward theplane 4- 4 and the resultant emission isuseful. If this construction were carried higher in the side ofthebowlthe prismfanglewould be increased and the proportion of lightwasted tween the lenssurfaccs 15 and 16. The

light received by it is already deviated sufficiently so this section ofthe outer bowl is left smooth. Section 26 is opposed tothat part ofsection 12, Fig. 1 lying between lens surface 16 and extreme lenssurface 18.

Light rays received by section 26 are already depressed to the requiredvertical angle and are refracted transversely by the vertical prismsthereon so that they are concentrated toward the plane 4-4 and assist inlighting the road strip more distant from the luminaire. In order totake care of the light from section 13, Fig. 1 which cannot be handledby section 25, section 26 is extended below the horizontal plane ofdivision 11 in Figs. 1 and 3 to join the prismatic construction onsection 25. Section 25 and section 26 merge as shown in order to mergethe resultant beams from the two sections. i i

Such a construction as that described will I have a tendency to reducethe light emitted directly downward to some-what too great a degree.This is readily taken care of, however, by cutting away a small portionof the lens surfaces in the very lowest part of the inside bowl so thata certain portion of the light rays will be transmitted without verticaldeviation.

In Fig. 5, 29 is a reflector of hemispherical contour with its centre atthe centre of the light source 7. Typical light rays proceeding upwardfrom the source 7 are reflected back on their paths through the sourceand to the globe along the same path as typical light rays 31,transmitted downward direct from the source. The reflector, therefore,increases the intensity of the light delivered by the globe withoutchanging its distribution.

In Fig. 6, 32 is a reflector having a lower part 33 of hemisphericalcontour with centre at 7 and typical ray 30 is reflected back throughthe source to coincide with'direct ray 31, and both direct and reflectedrays will be emitted by the globe in direction 41. The upper part 34 ofreflector 32 is a sur face of revolution the contour of which invertical section is that of an ellipse with 7 as one focus and 35 as itssecond focus. Typical ray 36 proceeding upward from the source 7 will bereflected back in direction angles and does not contribute anything tothe beam at low angles.

I claim: l. A luminaire of spherical formation having on one surface aseries of annular refracting ribs with axes lying in the same plane andopposed thereto a series of prismatic ribs decreasing in angularitytoward the plane of the axes and lying parallel thereto, the apices ofsuch prisms being pointed toward such plane and adapted to give alateral concentration to the cones of light produced by the annularribs.

2. A luminaire of spherical formation having on one surface a series ofannular refracting ribs with axes lying in the same plane and ofsuccessively increasing inclination with reference to the innermostannulus and opposed thereto a series of prismatic ribs decreasing inangularity toward the plane of the axes and lying parallel thereto, theapices of such prisms being pointed toward such plane and adapted togive a lateral concentration to the cones of light produced by theannular ribs.

. 3. A luminaire of spherical formation having one surface divided intoupper and lower sections each section provided with annular ribs withtheir axes inclined to the vertical, the ribs forming the upper sectionbeing adapted to concentrate the light rays toward the axial plane andto depress them below a definite angular limit, the lower section havingribs thereon adapted to deflect the light toward the axial plane with amore moderate degree of concentration, and opposed to such annular ribsa series of prismatic ribs decreasing in angularity toward the plane ofthe axes and lying parallel thereto, the apices of such prisms'beingpointed toward such plane and adapted to give a lateral concentration tothe cones of light produced by the annular ribs.

,4. A luminaire of spherical formation having on one surface a. seriesof annular refracting ribs with axes lying in the same plane and opposedto such annular ribs a central zone having prismatic ribs decreasing inangularity toward the plane of the axes and lying parallel thereto, theapices of such prisms being pointed toward such plane, and adjacent tosuch central zone, zones of vertical radial prismatic ribs of similarcharacteristics, such opposed zones being adapted to give lateralconcentration to the cones of light produced by the annular ribs.

5. A luminaire of spherical formation having one surface divided intoupper and lower sections each section provided with annular ribs withtheir axes inclined to the vertical, the ribs forming the upper sectionbeing'adapted to concentrate the light rays toward the axial plane andto depress them below a definite angular limit, the lower section havingannular ribs thereon adapted to deflect the light toward the axial planewith a more moderate degree of concentration and opposed to such annularribs a central zone having prismatic ribs decreasing in angularitytoward the plane of the axes and lying parallel thereto, the apices ofsuch prisms being pointed toward such plane, and

adjacent to such central zone, zones of vertical radialprismatic ribs ofsimilar characteristics, such opposed zones being adapted to givelateral concentration tothe cones of light produced by the annular ribs.

Signed at Newark, in the county of Licking and State of Ohio, this 10thday of June, 1927.

WILLIAM A. DoREYf

